Resistant starch type III (RS3 ) was produced from sago (Metroxylon sagu) and evaluated for its characteristics as a prebiotic. Two RS3 samples designated sago RS and HCl-sago RS contained 35.71% and 68.30% RS, respectively, were subjected to hydrolyses by gastric juice and digestive enzymes and to absorption. Both sago RS and HCl-sago RS were resistant to 180 min hydrolysis by gastric acidity at pH 1 to 4 with less than 0.85% hydrolyzed. Both samples were also resistant toward hydrolysis by gastrointestinal tract enzymes and intestinal absorption with 96.75% and 98.69% of RS3 were recovered respectively after 3.5 h digestion and overnight dialysis at 37 °C. Sago RS3 supported the growth of both beneficial (lactobacilli and Bifidobacteria) and pathogenic microbes (Escherichia coli, Campylobacter coli, and Clostridium perfringens) in the range of 2.60 to 3.91 log10 CFU/mL. Hence, prebiotic activity score was applied to describe the extent to which sago RS3 supports selective growth of the lactobacilli and bifidobacteria strains over pathogenic bacteria. The highest scores were obtained from Bifidobacterium sp. FTDC8943 grown on sago RS (+0.26) and HCl-sago RS (+0.24) followed by L. bulgaricus FTDC1511 grown on sago RS (+0.21). The findings had suggested that sago RS3 has the prebiotic partial characteristics and it is suggested to further assess the suitability of sago RS3 as a prebiotic material.
This study aimed at utilizing ultrasound treatment to further enhance the growth of lactobacilli and their isoflavone bioconversion activities in biotin-supplemented soymilk. Strains of lactobacilli (Lactobacillus acidophilus BT 1088, L. fermentum BT 8219, L. acidophilus FTDC 8633, L. gasseri FTDC 8131) were treated with ultrasound (30 kHz, 100 W) at different amplitudes (20%, 60% and 100%) for 60, 120 and 180 s prior to inoculation and fermentation in biotin-soymilk. The treatment affected the fatty acids chain of the cellular membrane lipid bilayer, as shown by an increased lipid peroxidation (P<0.05). This led to increased membrane fluidity and subsequently, membrane permeability (P<0.05). The permeabilized cellular membranes had facilitated nutrient internalization and subsequent growth enhancement (P<0.05). Higher amplitudes and longer durations of the treatment promoted growth of lactobacilli in soymilk, with viable counts exceeding 9 log CFU/mL. The intracellular and extracellular β-glucosidase specific activities of lactobacilli were also enhanced (P<0.05) upon ultrasound treatment, leading to increased bioconversion of isoflavones in soymilk, particularly genistin and malonyl genistin to genistein. Results from this study show that ultrasound treatment on lactobacilli cells promotes (P<0.05) the β-glucosidase activity of cells for the benefit of enhanced (P<0.05) isoflavone glucosides bioconversion to bioactive aglycones in soymilk.
The objective of the present study was to evaluate the effect of electroporation on the membrane properties of lactobacilli and their ability to remove cholesterol in vitro. The growth of lactobacilli cells treated at 7.5 kV/cm for 4 ms was increased by 0.89 to 1.96 log(10) cfu/mL upon fermentation at 37 °C for 20 h, the increase being attributed to the reversible and transient formation of pores and defragmentation of clumped cells. In addition, an increase of cholesterol assimilation as high as 127.2% was observed for most cells electroporated at a field strength of 7.5 kV/cm for 3.5 ms compared with a lower field strength of 2.5 kV/cm. Electroporation also increased the incorporation of cholesterol into the cellular membrane, as shown by an increased cholesterol:phospholipids ratio (50.0-59.6%) upon treatment at 7.5 kV/cm compared with treatment at 2.5 kV/cm. Saturation of cholesterol was observed in different regions of the membrane bilayer such as upper phospholipids, apolar tail, and polar heads, as indicated by fluorescence anisotropy using 3 fluorescent probes. Electroporation could be a useful technique to increase the ability of lactobacilli to remove cholesterol for possible use as cholesterol-lowering adjuncts in the future.
Matched MeSH terms: Lactobacillus/growth & development
The objective of the present study was to evaluate the effects of ultrasound on the growth of probiotics and bioconversion of isoflavones in prebiotic-soymilk. Previous studies have shown that ultrasound elevated microbial enzymatic activity and growth by altering cellular membranes. The growth of probiotics was significantly decreased (P < 0.05) immediately after ultrasound treatment, attributed to membrane permeabilization, cell lysis, and membrane lipid peroxidation upon ultrasound treatment. The ultrasound treatment also caused alteration at the acyl chain, polar head, and interface region of the probiotic membrane phospholipid bilayers. The cells treated with ultrasound showed recovery from injury with subsequent increase in growth upon fermentation in soymilk (P < 0.05). Ultrasound treatment at 100 W for 2 and 3 min also enhanced (P < 0.05) the intracellular and extracellular β-glucosidase activity of probiotics, leading to increased (P < 0.05) bioconversion of glucosides to aglycones in the prebiotic-soymilk. Our present study illustrated that ultrasound treatment could produce bioactive synbiotic-soymilk with increased concentrations of bioactive aglycones.
Matched MeSH terms: Lactobacillus/growth & development
A comparative study on the stability and potential of alginate and pectin based beads for production of poultry probiotic cells using MRS medium in repeated batch fermentation was conducted. The bead cores, made of three types of materials, i.e., ca-alginate, ca-pectinate and ca-alginate/pectinate, were compared. The effect of single and double layer coatings using chitosan and core material, respectively, on the bead stability and cell production were also studied. The pectin based beads were found to be more stable than that of the alginate beads and their stability was further improved by coating with chitosan. The cell concentration in pectin based beads was comparable to that in the alginate beads. On the other hand, pectin based beads gave significantly lower cell concentration in the growth medium for the initial fermentation cycles when compared to the alginate beads. In conclusion, pectin was found to be potential encapsulation material for probiotic cell production owing to its stability and favourable microenvironment for cell growth.
Matched MeSH terms: Lactobacillus/growth & development
This study was undertaken to optimize yeast extract, glucose, and vitamin concentrations; and also culture pH for maximizing the growth of a probiotic bacterium, Lactobacillus rhamnosus, and to assess the effects of these factors by using response surface methodology. A central composite design was used as an experimental design for the allocation of treatment combinations. A polynomial regression model with cubic and quartic terms was used for analysis of the experimental data. It was found that the effects involving yeast extract, glucose, vitamins and pH on the growth of L. rhamnosus were significant, and the strongest effect was given by the yeast extract concentration. Estimated optimum conditions of the factors for the growth of L. rhamnosus are as follows: pH=6.9; vitamin solution=1.28% (v/v); glucose=5.01% (w/v) and yeast extract=6.0% (w/v).
Tempoyak is a traditional Malaysian fermented condiment made from the pulp of the durian fruit (Durio zibethinus). Salt is sometime added to proceed fermentation at ambient temperature. In various samples obtained from night markets, lactic acid bacteria (LAB) were the predominant microorganisms, ranging from log 8.4 to log 9.2 cfu g(-1). No other microorganisms were present to such a level. These samples contained reduced amount of saccharose, glucose and fructose but increased amount of D- and L-lactic acid and acetic acid compared with samples of non-fermented durian fruit. Sixty-four isolates of LAB were divided into five groups by use of a few phenotypic tests. A total of 38 strains of LAB were selected for comparison by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of their whole cell protein patterns with a SDS-PAGE database of LAB. These strains were also examined for their carbohydrate fermentation patterns by use of API 50 CH. Isolates belonging to the Lactobacillus plantarum group were shown to be the predominant members of the LAB flora. In addition, isolates belonging to the Lactobacillus brevis group, Leuconostoc mesenteroides, Lactobacillus mali, Lactobacilus fermentum and an unidentified Lactobacillus sp. were also observed. A high degree of diversity among isolates belonging to the Lb. plantarum group was demonstrated by analysis of their plasmid profiles.
Matched MeSH terms: Lactobacillus/growth & development
1. The effects of a mixture of 12 Lactobacillus strains (LC) on the growth performance, abdominal fat deposition, serum lipids and weight of organs of broiler chickens were studied from 1 to 42 d of age. 2. One hundred and thirty-six 1-d-old male broiler chicks were assigned at random to two dietary treatments: a basal diet (control), and a basal diet with 0.1% LC. 3. The supplementation of LC in broiler diets improved the body weight gain and feed conversion rate from 1 to 42 d of age and was effective in reducing abdominal fat deposition but only after 28 d of age. 4. The LC diets reduced serum total cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides in broilers from 21 to 42 d of age. However, there was no significant difference in serum high density lipoprotein (HDL) cholesterol between control and LC-fed broilers. There was also no significant difference in the weights of organs of control and LC-fed broilers. 5. The results indicated that the mixture of 12 Lactobacillus strains have a hypolipidaemic effect on broilers.
Kefir is a homemade, natural fermented product comprised of a probiotic bacteria and yeast complex. Kefir consumption has been associated with many advantageous properties to general health, including as an antioxidative, anti-obesity, anti-inflammatory, anti-microbial, and anti-tumor moiety. This beverage is commonly found and consumed by people in the United States of America, China, France, Brazil, and Japan. Recently, the consumption of kefir has been popularized in other countries including Malaysia. The microflora in kefir from different countries differs due to variations in culture conditions and the starter media. Thus, this study was aimed at isolating and characterizing the lactic acid bacteria that are predominant in Malaysian kefir grains via macroscopic examination and 16S ribosomal RNA gene sequencing. The results revealed that the Malaysian kefir grains are dominated by three different strains of Lactobacillus strains, which are Lactobacillus harbinensis, Lactobacillusparacasei, and Lactobacillus plantarum. The probiotic properties of these strains, such as acid and bile salt tolerances, adherence ability to the intestinal mucosa, antibiotic resistance, and hemolytic test, were subsequently conducted and extensively studied. The isolated Lactobacillus spp. from kefir H maintained its survival rate within 3 h of incubation at pH 3 and pH 4 at 98.0 ± 3.3% and 96.1 ± 1.7% of bacteria growth and exhibited the highest survival at bile salt condition at 0.3% and 0.5%. The same isolate also showed high adherence ability to intestinal cells at 96.3 ± 0.01%, has antibiotic resistance towards ampicillin, penicillin, and tetracycline, and showed no hemolytic activity. In addition, the results of antioxidant activity tests demonstrated that isolated Lactobacillus spp. from kefir G possessed high antioxidant activities for total phenolic content (TPC), total flavonoid content (TFC), ferric reducing ability of plasma (FRAP), and 1,1-diphenyl-2-picryl-hydrazine (DPPH) assay compared to other isolates. From these data, all Lactobacillus spp. isolated from Malaysian kefir serve as promising candidates for probiotics foods and beverage since they exhibit potential probiotic properties and antioxidant activities.
Matched MeSH terms: Lactobacillus/growth & development
Twelve Lactobacillus strains isolated from chicken intestine were used to investigate acid and bile tolerance in vitro. Ten out of the 12 strains were slightly affected by 0.3% bile salts, showing a delay of growth (d) of 0.6-37.2 min compared with growth in control cultures. Two strains were not affected by the bile salts. Of the 12 strains, seven could be arbitrarily classified as resistant (d < 15 min) and five as tolerant (15 min < d < or = 40 min). Lactobacillus strains from the caecum showed better tolerance to acid than those from the ileum. Generally, the survival of the ileal strains was very low at pH 1.0 and 2.0, and moderate at pH 3.0. In contrast, caecal Lactobacillus strains could survive at pH 1.0 for up to 2 h of incubation; growth was moderate at pH 2.0 and good at pH 3.0 and 4.0.
The biofilm degradation of Aggregatibacter actinomycetemcomitans is essential as a complete periodontal disease therapy, and here we show the effects of potential probiotic bacteria such as Lactobacillus spp. for the biofilm of several serotypes of A. actinomycetemcomitans strains. Eight of the 13 species showed the competent biofilm degradation of ≥ 90% reduction in biofilm values in A. actinomycetemcomitans Y4 (serotype b) as well as four of the seven species for the biofilm of A. actinomycetemcomitans OMZ 534 (serotype e). In contrast, the probiotic bacteria did not have a big impact for the degradation of A. actinomycetemcomitans SUNY 75 (serotype a) biofilm. The dispersed A. actinomycetemcomitans Y4 cells through the biofilm detachment were still viable and plausible factors for the biofilm degradation were not due to the lactic acid and low pH conditions. The three enzymes, protease, lipase, and amylase may be responsible for the biofilm degradation; in particular, lipase was the most effective enzyme for the biofilm degradation of A. actinomycetemcomitans Y4 along with the protease activity which should be also important for the other serotypes. Remarkable lipase enzyme activities were detected from some of the potential probiotics and a supporting result using a lipase inhibitor presented corroborating evidence that lipase activity is one of the contributing factors for biofilm degradation outside of the protease which is also another possible factor for the biofilm of the other serotype of A. actinomycetemcomitans strains. On the other hand, the biofilm of A. actinomycetemcomitans SUNY 75 (serotype a) was not powerfully degraded by the lipase enzyme because the lipase inhibitor was slightly functional for only two of potential probiotics.
This study aimed at utilizing electroporation to further enhance the growth of lactobacilli and their isoflavone bioconversion activities in biotin-supplemented soymilk. Strains of lactobacilli were treated with different pulsed electric field strength (2.5, 5.0 and 7.5 kV/cm) for 3, 3.5 and 4 ms prior to inoculation and fermentation in biotin-soymilk at 37°C for 24 h. Electroporation triggered structural changes within the cellular membrane of lactobacilli that caused lipid peroxidation (p growth to >9 log CFU/ml after fermentation in biotin-soymilk (p
Soy products have attracted much attention lately as carriers for probiotics. This study was aimed at enhancing the growth of probiotics in soymilk via supplementation with prebiotics.
The aim of this study was to evaluate the effects of ultraviolet (UV) radiation (ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC) at 30-90 J/m²) on the membrane properties of lactobacilli and bifidobacteria, and their bioconversion of isoflavones in prebiotic-soymilk. UV treatment caused membrane permeabilization and alteration at the acyl chain, polar head and interface region of membrane bilayers via lipid peroxidation. Such alteration subsequently led to decreased (p < 0.05) viability of lactobacilli and bifidobacteria immediately after the treatment. However, the effect was transient where cells treated with UV, particularly UVA, grew better in prebiotic-soymilk than the control upon fermentation at 37°C for 24 h (p < 0.05). In addition, UV treatment also increased (p < 0.05) the intracellular and extracellular β-glucosidase activity of lactobacilli and bifidobacteria. This was accompanied by an increased (p < 0.05) bioconversion of glucosides to bioactive aglycones in prebiotic-soymilk. Our present study illustrated that treatment of lactobacilli and bifidobacteria with UV could develop a fermented prebiotic-soymilk with enhanced bioactivity.
Matched MeSH terms: Lactobacillus/growth & development
Cell immobilization is an alternative to microencapsulation for the maintenance of cells in a liquid medium. The objective of this study was to evaluate the effects of agrowastes from durian (Durio zibethinus), cempedak (Artocarpus champeden), and mangosteen (Garcinia mangostana) as immobilizers for lactobacilli grown in soymilk. Rinds from the agrowastes were separated from the skin, dried, and ground (150 microm) to form powders and used as immobilizers. Scanning electron microscopy revealed that lactobacilli cells were attached and bound to the surface of the immobilizers. Immobilized cells of Lactobacillus acidophilus FTDC 1331, L. acidophilus FTDC 2631, L. acidophilus FTDC 2333, L. acidophilus FTDC 1733, and L. bulgaricus FTCC 0411 were inoculated into soymilk, stored at room temperature (25 degrees C) and growth properties were evaluated over 168 h. Soymilk inoculated with nonimmobilized cells was used as the control. Utilization of substrates, concentrations of lactic and acetic acids, and changes in pH were evaluated in soymilk over 186 h. Immobilized lactobacilli showed significantly better growth (P < 0.05) compared to the control, accompanied by higher production of lactic and acetic acids in soymilk. Soymilk containing immobilized cells showed greater reduction of soy sugars such as stachyose, raffinose, sucrose, fructose, and glucose compared to the control (P < 0.05).
Ten strains of Lactobacillus were evaluated for their viability in soymilk. Lactobacillus acidophilus ATCC 314, L. acidophilus FTDC 8833, L. acidophilus FTDC 8633 and L. gasseri FTDC 8131 displayed higher viability in soymilk and were thus selected to be evaluated for viability and growth characteristics in soymilk supplemented with B-vitamins. Pour plate analyses showed that the supplementation of all B-vitamins studied promoted the growth of lactobacilli to a viable count exceeding 7 log CFU/ml. alpha-Galactosidase specific activity of lactobacilli as determined spectrophotometrically showed an increase upon supplementation of B-vitamins. High-performance liquid chromatography analyses revealed that this led to increased hydrolysis of soy oligosaccharides and subsequently higher utilization of simple sugars. Production of organic acids as determined via high-performance liquid chromatography also showed an increase, accompanied by a decrease in pH of soymilk. Additionally, the supplementation of B-vitamins also promoted the synthesis of riboflavin and folic acid by lactobacilli in soymilk. Our results indicated that B-vitamin-supplemented soymilk is a good proliferation medium for strains of lactobacilli.
Probiotic delivery system was developed via the use of microbial transglutaminase (MTG) cross-linked soy protein isolate (SPI) incorporated with agrowastes such as banana peel (BE), banana pulp (BU), and pomelo rind (PR). Inoculums of Lactobacillus bulgaricus FTDC 1511 were added to the cross-linked protein matrix. The incorporation of agrowastes had significantly (P<0.05) reduced the strength, pH value, and the lightness of the SPI gel carriers, while sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles revealed that the occurring cross-links within the SPI gel carriers were attributed to the addition of MTG. Scanning electron microscope micrographs illustrated that SPI carriers containing agrowastes have exhibited a less-dense protein matrix. All the SPI carriers possessed maximum swelling ratio at 4 to 4.5 within 15 min in simulated gastric fluid (SGF), whereas the maximum swelling ratios of SPI/BE, SPI/BU, and SPI/PR were higher compared to that of control in simulated intestinal fluid (SIF). Additionally, SPI carriers in SGF medium did not show degradation of structure, whereas a major collapse of network was observed in SIF medium, indicating controlled-release in the intestines. The addition of agrowastes into SPI carriers led to a significantly (P<0.0001) lower release of L. bulgaricus FTDC 1511 in SGF medium and a higher release in SIF medium, compared to that of the control. SPI carriers containing agrowastes may be useful transports for living probiotic cells through the stomach prior to delivery in the lower intestines.
Matched MeSH terms: Lactobacillus/growth & development